1、Designation: E2548 111Standard Guide forSampling Seized Drugs for Qualitative and QuantitativeAnalysis1This standard is issued under the fixed designation E2548; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEditorial corrections were made to Sections 1 and 8 in December 2011.1. Scope1.1 This guide covers minimum considerations for sampling
3、of seized drugs for qualitative and quantitative analysis.1.2 This guide cannot replace knowledge, skill, or abilityacquired through appropriate education, training, and experi-ence and should be used in conjunction with sound profes-sional judgment.2. Referenced Documents2.1 ASTM Standards:2E105 Pr
4、actice for Probability Sampling of MaterialsE122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE141 Practice for Acceptance of Evidence Based on theResults of Probability SamplingE1732 Terminology Relating to Forensic Sc
5、ienceE2329 Practice for Identification of Seized DrugsE2334 Practice for Setting an Upper Confidence Bound Fora Fraction or Number of Non-Conforming items, or a Rateof Occurrence for Non-conformities, Using Attribute Data,When There is a Zero Response in the Sample2.2 ISO Standards:3ISO 3534-1 Stati
6、stics Vocabulary and Symbols Part 1:Probability and General Statistical TermsISO 3534-2 Statistics Vocabulary and Symbols Part 2:Statistical Quality Control3. Significance and Use3.1 This guide provides information for the sampling ofseized-drug submissions.3.2 The principal purpose of sampling in t
7、he context of thisguide is to answer relevant questions about a population byexamination of a portion of the population. For example:What is the net weight of the population?What portion of the units of a population can be said to contain agiven drug at a given level of confidence?3.3 By developing
8、a sampling strategy and implementingappropriate sampling schemes, as illustrated in Fig. 1,alaboratory will minimize the total number of required analyti-cal determinations, while ensuring that all relevant legal andscientific requirements are met.4. Sampling Strategy4.1 A sampling strategy is highl
9、y dependent on the purposeof the investigation, the original question, and the ultimate useof the results. Laws and legal practices form the foundation ofmost strategies and shall be taken into account when designinga sampling scheme. Therefore, specific sampling strategies arenot defined in this gu
10、ide.4.2 The laboratory has the responsibility to develop its ownstrategies consistent with these recommendations. It is recom-mended that the following key points be addressed:4.2.1 Sampling may be statistical or non-statistical.NOTE 1For the purpose of this guide, the use of the term statistical is
11、meant to include the notion of an approach that is probability-based.4.2.1.1 In many cases, a non-statistical approach may suf-fice. The sampling plan shall provide an adequate basis foranswering questions of applicable law. For example,Is there a drug present in the population?Are statutory enhance
12、ment levels satisfied by the analysis of aspecified number of units?4.2.1.2 If an inference about the whole population is to bedrawn from a sample, then the plan shall be statistically basedand limits of the inference shall be documented.4.2.2 Statistically selected units shall be analyzed to meetPr
13、actice E2329 if statistical inferences are to be made about thewhole population.1This guide is under the jurisdiction of ASTM Committee E30 on ForensicSciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved Sept. 1, 2011. Published October 2011. Or
14、iginallyapproved in 2007. Last previous version approved in 2007 as E2548 07. DOI:10.1520/E2548-11E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards
15、Document Summary page onthe ASTM website.3Available from International Organization for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unite
16、d States.5. Sampling Scheme5.1 The sampling scheme is an overall approach that in-cludes population determination, selection of the sampling planand procedure and, when appropriate, sample reduction prior toanalysis (Fig. 2).5.2 Population Determination:5.2.1 The population determination shall take
17、into accountall typical forms and quantities in which exhibits may appear.5.2.2 A population can consist of a single unit or multipleunits.FIG. 1 Relationship of Various Levels Required in SamplingFIG. 2 Example of a Sampling SchemeA Decision FlowchartE2548 11125.2.3 A multiple unit population shall
18、 consist of items thatare similar in relevant visual characteristics.SAMPLING PLAN5.3 There are numerous sampling plans used in the forensicanalysis of drugs that are applicable to single and multiple unitpopulations.5.4 When a single unit or bulk population is to be analyzed,the issue of homogeneit
19、y shall be addressed within the sam-pling plan.5.4.1 One sample is sufficient if the bulk material is homo-geneous. Analysts can make bulk material homogeneous.5.4.2 If the bulk material is not homogeneous, severalsamples from different locations may be necessary to ensurethat the test results are r
20、epresentative of the bulk material andto avoid false negative results.5.5 Depending upon the inference to be drawn from theanalysis for a multiple unit population, the sampling plan maybe statistical or non-statistical.5.5.1 Statistical approaches are applicable when inferencesare made about the who
21、le population. For example:The probability that a given percentage of the population containsthe drug of interest or is positive for a given characteristic.The total net weight of the population is to be extrapolated from theweight of a sample.5.5.1.1 Published examples of statistical approaches inv
22、olv-ing general considerations:(1) Practice E105.(2) Practice E141.(3) Terminology E1732.(4) Guidelines on Representative Drug Sampling.4(5) ISO 3534-1.(6) ISO 3534-2.5.5.1.2 Published examples of statistical approaches involv-ing the hypergeometric, normal, and other distributions from afrequentist
23、 perspective:(1) Frank, et al., Journal of Forensic Sciences.5(2) Guidelines on Representative Drug Sampling.4(3) Practice E2334.(4) Practice E122.5.5.1.3 Published examples of statistical approaches involv-ing the hypergeometric, normal, and other distributions from aBayesian perspective:(1) Coulso
24、n, et al., Journal of Forensic Sciences.6(2) Guidelines on Representative Drug Sampling.45.5.2 Non-statistical approaches are appropriate if no infer-ence is to be made about the whole population.5.5.2.1 Published examples:(1) The “square root method.”7(2) Methods listed in “Arbitrary Sampling” in G
25、uidelineson Representative Drug Sampling.45.5.2.2 Selection of a single unit from a multiple unitpopulation may be appropriate under certain circumstances (forexample, management directives and legislative or judicialrequirements, or both).5.6 Sampling Procedure:5.6.1 Establish the procedure for sel
26、ecting the number ofunits that will comprise a sample.5.6.1.1 For non-statistical approaches, select a sample ap-propriate for the analytical objectives.5.6.1.2 For statistical approaches it is recommended thatrandom sampling be conducted.5.6.2 Select a Random Sample:5.6.2.1 A random sample is one s
27、elected without bias.Computer generated random numbers or random number tablesare commonly employed for such tasks and these should beincluded in the sampling plan.5.6.2.2 Random sampling of items using random numbertables may not be practical in all cases. In these instances, analternate sampling p
28、lan shall be designed and documented toapproach random selection. A practical solution involves a“black box” method, which refers to one that will prevent thesampler from consciously selecting a specific item from thepopulation (that is, all units are placed in a box and the samplesfor testing are s
29、elected without bias). Random sampling isdiscussed in the following references:(1) Practice E105.(2) Frank, et al., Journal of Forensic Sciences.5(3) ISO 3534-1.(4) ISO 3534-2.5.7 Sample ReductionSample reduction may be applied incases where the weight or volume of the selected units is toolarge for
30、 laboratory analysis (Fig. 2, insert A).6. Analysis6.1 Statistically Selected Sample(s)In accordance with4.2.2, it is recommended that each unit comprising the samplebe analyzed to meet Practice E2329 if statistical inferences areto be made about the whole population.6.2 Non-statistically Selected S
31、ample(s)Practice E2329shall be applied to at least one unit of the sample.7. Documentation7.1 Inferences based on use of a sampling plan and con-comitant analysis shall be documented.8. Reporting8.1 Sampling information shall be included in reports.8.1.1 Statistically Selected Sample(s)Reporting sta
32、tisticalinferences for a population is acceptable when testing isperformed on the statistically selected units as stated in 6.1above. The language in the report must make it clear to thereader that the results are based on a sampling plan.8.1.2 Non-Statistically Selected Sample(s)The languagein the
33、report must make it clear to the reader that the resultsapply to only the tested units. For example, 2 of 100 bags wereanalyzed and found to contain Cocaine.4Guidelines on Representative Drug Sampling, European Network of ForensicScience Institutes (ENFSI), 2004, http:/www.ENFSI.org.5Frank et al., “
34、Representative Sampling of Drug Seizures in Multiple Contain-ers,” Journal of Forensic Sciences, , Vol 36, No. 2, 1991, pp. 350357.6Coulson et al., “How Many Samples from a Drug Seizure Need to BeAnalyzed?,” Journal of Forensic Sciences, Vol 46, No. 6, 2001, pp. 14561461.7Recommended Methods for Tes
35、ting Opium, Morphine and Heroin: Manual forUse by National Drug Testing Laboratories, United Nations Office on Drugs andCrime, 1998.E2548 11139. Keywords9.1 analytical method; qualitative method; quantitativemethod; sampling; seized drug analytical methodASTM International takes no position respecti
36、ng the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This stand
37、ard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Internation
38、al Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.T
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